Well, it really depends the program you have.
Step one is opening the image with IE or firefox. Then copy the image to;
MS Word or open office; open up the picture's properties and change the size of the image's larger dimension to 1 inch. make sure the option to maintain proportions is activated. MS word seems to autosmooth the image so it will actually look less pixel-ated as you stretch it. [I combo this with a 'printscreen' to make much smother large critters like the greater medusa [TBH lamia] in the petrifier grouping upthread, this has the side effect of making the imaage much larger however if saved}
Paint; once you paste an image into a blank field, bigger than the image. make a 96 pixel box near the image. Then stretch the image to fit within the box. [ Paint generally sets image size to 96 pixels to the inch].
...Or tell me which images ya want on how large a sheet your printer can handle and I'll see what i can do for ya. I've been assuming most colour printers should not need more than half an inch for margins, thus 7x10 is the grid i've been deploying the units on.